Geo 730: July 14, Day 560: Congratulations! It's a Conifer!

In this shot, we can see enough detail for me to be able to tell it's a conifer. How? Coniferous wood is dominated by a single cell type, tracheids, which make up 90-95% of the tissue volume. Deciduous wood has a greater variety of cell types, with greater specialization, and a more "disorganized" (my own mental construct) overall look. See this link for a nice introduction; the tissue diagrams on the right are the pertinent illustrations. Even at full size (see crop below), you can't make out much cellular-level detail, but you can tell the cells are in a nice, tidy "brick wall" style of organization (again, my own mental construct).

An interesting point to note is that the summer wood, because it has a smaller cell wall to volume ratio (larger cells) than winter wood, has lower local strength than winter wood, and sometimes collapses during burial and lithification, as shown in the annotation below. I have a very nice photomicrograph coming up to illustrate this point.

 Photo unmodified. March 9, 2012. FlashEarth location.